Tires with high strength reinforcement

ABSTRACT

A strip of tire ply stock is reinforced with steel cords wherein the steel cords are constructed of high strength wire filament having at least a tensile strength of −2000×D+4400 MPa where D is the filament diameter in mm. Tires are constructed with the ply stock in the belt and/or carcass.

[0001] The present invention relates to cord, cord reinforced plies andradial tires for vehicles. Radial tires are those tires wherein thecords of the carcass plies, which extend from one bead to the other, liesubstantially on radial planes. More particularly, the present inventionrelates to a structure of one or more plies formed of a cord reinforcedcomposite having rubber where preferably the structure is for tires,such as for a tire carcass or a tire belt wherein at least one of theplies in the carcass or belt has the cords therein biased with respectto the direction of rotation of the tire.

[0002] Reinforced elastomeric articles are well known in the art. Forexample, conveyor or like type belts, tires, etc., are constructed withcords of textile and/or fine steel wire filaments or strands. Inparticular, belts used in pneumatic tires are constructed of up to eightply layers with the cord reinforcement of adjacent plies being biasedwith respect to the direction of movement of the tire where it isdesired to reinforce in both the lateral direction and the direction ofrotation of the tire. Further, cords made of strands of multi-twistedfilaments of fine wire with a single strand construction having two ormore filaments and a wrap filament thereabout to reinforce the cordstructure have also been known. In some cases, the reinforcementincludes the use of single strand cords of multi-filaments which are nottwisted about each other but rather twisted altogether as a bundle orbunch (bunched cord) to simplify the cord construction, as disclosed inassignees's U.S. Pat. No. 4,947,636 which is incorporated by referencein its entirety herein. Higher fatigue life requirements for compositesin tires have resulted in cords with smaller filament diameter requiringmore filaments in the cord to obtain the necessary strength.

[0003] Two ply tire belts for passenger and light truck tires can havecords of 2x0.255ST and 2+2x0.32-0.40ST, respectively. An example of thefirst construction is described in Assignee's Statutory InventionRegistration H1333, issued Jul. 5, 1994, which application isincorporated by reference in its entirety herein, wherein multi-filamentcords such as 2X0.255ST are disclosed. This designation means one cordof two (2) 0.255 mm. diameter filaments. An example of the2+2x0.32-.40ST cord is disclosed in Assignee's U.S. Pat. No. 5,242,001,which is incorporated in its entirety by reference herein. Thisdesignation means one cord of four (4) 0.32-0.40 mm. diameter filaments(with two (2) filaments twisted at a shorter lay length than the othertwo (2) filaments). Multi-filament cords such as 2+2x0.32-.40ST havebeen found necessary to meet the higher demand of strength forcomposites in tire belts, typically used in light truck applications.Both of these cords were made of super tensile (ST) steel as definedhereinafter. Though cord designs incorporating super tensile (ST) steelhave proven effective, there is a continuing need to develop lighterweight cord constructions with improved characteristics, such as highercorrosion propagation resistance and improved tire performance, overrecent high tensile and super tensile constructions.

[0004] The described cord constructions generally have not found use inlarger tires, such as off-the-road (OTR) tires, because they were notstrong enough. Even with the advent of high tensile filament such as inAssignee's 2+2x cord, disclosed for use in passenger and light trucktires, the large OTR tires continue to use traditional constructionssuch as 7x7x0.25+1HT and 3x7x0.22HE comprising seven strands each ofseven 0.25 mm diameter high tensile filaments that are twisted togetherand spiral-wrapped; and three strands each of seven 0.22 mm diameterhigh tensile filaments that are twisted together, respectively. Thesteel cord cable currently used for ply reinforcement in OTR tires forsizes 36.00R51 and larger is stranded cord of high tensile tire cordfilament such as 7x19x0.20+1HT cord comprising seven strands each ofnineteen 0.20 mm diameter high tensile filaments that are twistedtogether and spiral-wrapped. These cords were made of high tensile (HT)steel as defined hereinafter.

[0005] More recently, OTR tires can be constructed of multiple pliesbelts or single ply with reinforcing cords such as 27x0.265ST or5+8+14x0.265ST+1 as disclosed in Assignee's U.S. Pat. No. 5,318,643which patent is incorporated by reference in its entirety herein. Still,current steel cord constructions have breaking load and cable gaugelimitations preventing the needed design inch-strength from beingachieved for tires larger than 40.00R57 used on trucks and earthmoversweighing up to and sometimes more than 320 tons. In addition, there is aneed to increase the rivet area in the ply and belt, i.e., the spacebetween the cords, for tire sizes of 36.00R51 and larger so that morerubber can penetrate between the cords during tire manufacture toenhance the quality of calendered treatment by preventing “weak rivet”or “loose coat” (which can result in trapped air in tires).

[0006] Many problems have had to be overcome even after development ofthe above higher strength filaments and cords. The higher strength steelalloys resulted in changes in cord modulus giving rise to thepossibility of adjusting the parameters of a tire belt gross load whichdepends upon three factors assuming adequate cord to rubber adhesion.The factors are cord modulus, the ratio of cord volume to rubber volume(often expressed as the number of cord ends per inch (epi)), and theangle of cord reinforcement. Further, as the angle of cord reinforcementapproaches the direction of rotation of the tire, the support from thereinforcement in the lateral direction moves toward zero. An increase inthe above-mentioned two other cord related factors, i.e., the cordmodulus and the ratio of cord volume to rubber volume, generally resultsin an increase of weight for the belt. Added weight can mean added cost,higher rolling resistance and lower fuel economy of a tire. Simply usinglighter cords with a lower modulus does not solve the problem because,even though they have lower weight, the lower cord modulus must beoffset by increasing the ratio of cord to rubber volume. This increasein cord volume is limited by the physical size of the cord and theresulting spacing between the cords which governs the amount of rivet,i.e., the ability of the rubber to penetrate between the cords for goodcord to rubber adhesion.

[0007] It is an object of the present invention to determine cordstructures which could take advantage of a new cord modulus while notadversely affecting cord volume to rubber volume ratio on lateralreinforcement so as to obviate the problems and limitations of the priorart tires and cord constructions.

[0008] It is another object of the present invention to provide cordstructures using ultra tensile wire which results in lighter weighttires.

[0009] It is still another object of the present invention to providecord structures using ultra tensile wire which results in tires withhigher corrosion propagation resistance and more rivet leading toimproved tire performance.

[0010] The present invention relates to a cord for reinforcing elastomerarticles of multiple filaments having a diameter (D) ranging from 0.10to 0.45 mm, each filament having at least a tensile strength of−2000×D+4400 MPa, where D is the filament diameter. These cords areparticularly useful in a carcass ply and/or belt structure of apneumatic tire.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 illustrates the cross section of a first embodiment of atire having a composite structure including two plies according to thepresent invention;

[0012]FIG. 2 illustrates a partial cross section of a second embodimentof a tire having a composite structure including four plies according tothe present invention;

[0013]FIG. 3 shows the cross section through a cord in accordance withan embodiment of the present invention;

[0014]FIG. 4 is a schematic illustration in cross section of acomposite, such as two abutted plies, in accordance with the presentinvention; and

[0015]FIGS. 5 through 16 show the cross section through a cord inaccordance with different embodiments of the present invention.

[0016] There is disclosed a cord for reinforcing elastomer articles ofmultiple filaments having a diameter (D) ranging from 0.10 to 0.45 mm,each filament having at least a tensile strength of −2000×D+4400 MPa,where D is the filament diameter. These cords are particularly useful ina carcass ply and/or belt structure of a pneumatic tire.

[0017] There is also disclosed a pneumatic tire with a carcass havingparallel cords, two sidewalls spaced apart a distance, which in theaxial direction determines the general width of the tire section, twobeads each one of which around which are turned up, from the insidetoward the outside, the ends of the cords of the carcass, a treaddisposed on the crown of said carcass, a belt structure that iscircumferentially inextensible interposed between the tread and thecarcass, and carcass plies disposed in said sidewalls between said twobeads and said crown of said carcass, said belt structure having a widththat is substantially equal to that of the tread and having carcassplies of elastomeric fabric reinforced with metallic cords, saidmetallic cords being comprised of a plurality of filaments having adiameter (D) ranging from 0.10 to 0.45 mm, each filament having atensile strength of −2000×D+4400 MPa, where D is the filament diameter.

[0018] In addition, there is disclosed a pneumatic tire with a carcasshaving parallel cords, two sidewalls spaced apart a distance, which inthe axial direction determines the general width of the tire section,two beads each one of which around which are turned up, from the insidetoward the outside, the ends of the cords of the carcass, a treaddisposed on the crown of said carcass, a belt structure that iscircumferentially inextensible interposed between the tread and thecarcass, and carcass plies disposed in said sidewalls between said twobeads and said crown of said carcass, said belt structure having a widththat is substantially equal to that of the tread and being constructedof at least one belt of elastomeric fabric reinforced with metalliccords, said metallic cords being comprised of a plurality of filamentshaving a diameter (D) ranging from 0.10 to 0.45 mm, each filament havinga tensile strength of −2000×D+4400 MPa, where D is the filamentdiameter.

[0019] After considerable study, effort, testing and time, the presentinvention provides cords and plies for passenger, light truck, truck,medium truck and OTR tires which substantially reduce the size andsometimes the number of filaments for the load ranges encompassed bythis range of tires. While the reduction in the number of filamentsleads one to expect a reduction in weight, this is not necessarily thecase since the prior art materials require that the filament size alsobe increased in order to obtain the needed strength for the tire.However, with the use of Ultra Tensile steel for the cord constructions,the number and/or the size of the filaments can be decreased whilemaintaining or even strengthening the tire. Under such circumstances,cord was found for use in the load ranges by varying the ends per inch(EPI) in the plies of the belt. Other advantages which exist in thepresent invention include lighter tires, improved rolling resistance,higher corrosion propagation resistance, and a reduction in the cordtreatment gauge between the cord layers in the belt. A weight reductiondue to a reduction in weight of reinforcement as well as a reduction inan amount of gum gauge also results in a reduction in manufacturing costand improved fuel economy for the tires of the present invention.Moreover, it is believed that improved temperature transfer can beachieved with the new cord designs of the invention to lengthen the lifeand improve the operating performance of tires incorporating thesecords. Further, the new belt structures give better rolling resistance,perhaps because of the lighter weight of the new cord designs ascompared with the old cord designs being used for reinforcement in thebelt structure.

[0020] As used herein and in the claims:

[0021] “Axial” and “axially” are used herein to refer to lines ordirections that are parallel to the axis of rotation of the tire.

[0022] “Bead” means that part of the tire comprising an annular tensilemember wrapped by ply cords and shaped, with or without otherreinforcement elements such as flippers, chippers, apexes, toe guardsand chafers, to fit the design of the tire rim.

[0023] “Belt structure” means at least two layers or plies of parallelcords, woven or unwoven, underlying the tread, unanchored to the bead,and having both left and right cord angles in the range from about 17 toabout 70 degrees with respect to the equatorial plane (EP) of the tire.

[0024] “Carcass” means the tire structure apart from the belt structure,the tread, the undertread and the sidewall rubber over the plies, butincluding the beads.

[0025] “Cord” means one or more of the reinforcement elements, formed bytwo or more filaments/wires which may or may not be twisted or otherwiseformed and which may further include strands that may or may not be alsoso formed, of which the plies in the tire are comprised.

[0026] “Crown” means that portion of the tire within the width limits ofthe tire tread.

[0027] “Density” means weight per unit length.

[0028] “Equatorial plane (EP)” means the plane perpendicular to thetire's axis of rotation and passing through the center of the tire'stread.

[0029] “Gauge” means material thickness.

[0030] “High Tensile Steel (HT)” means a carbon steel with a tensilestrength of at least 3400 Mpa @ 0.20 mm filament diameter.

[0031] “Super Tensile Steel (ST)” means a carbon steel with a tensilestrength of at least 3650 Mpa @ 0.20 mm filament diameter.

[0032] “Ultra Tensile Steel (UT)” means a carbon steel with a tensilestrength of at least 4000 Mpa @ 0.20 mm filament diameter.

[0033] “Load Range” means load and inflation limits for a given tireused in a specific type of service as defined by tables in The Tire andRim Association, Inc., 1989 Year Book.

[0034] “Radial” and “radially” are used to mean directions radiallyperpendicular from the axis of rotation through the tire.

[0035] “Rivet” means the open space between cords in a layer.

[0036] “Section width” means the maximum linear distance parallel to theaxis of the tire and between the exterior of its sidewalls when andafter it has been inflated at normal pressure for 24 hours, butunloaded, excluding elevations of the sidewalls due to labeling,decoration or protective bands.

[0037] “Stiffness ratio” means the value of the control belt structurestiffness divided into the value of another belt structure stiffnesswhen the values are determined by a fixed three (3) point bending testhaving both ends of the cord supported and flexed by a load centeredbetween the fixed ends.

[0038] The cords of the present invention may comprise of a number ofconstructions both with or without a spiral wrap. For example,representative constructions include 2x, 3x, 4x, 5x, 6x, 7x, 8x, 11x,12x, 27x, 1+2, 1+3, 1+4, 1+5, 1+6, 1+7, 1+8, 1+14, 1+15, 1+16, 1+17,1+18, 1+19, 1+20, 1+26, 2+2, 2+5, 2+6, 2+7, 2+8, 2+9, 2+10, 2/2, 2/3,2/4, 2/5, 2/6, 3+2, 3+3, 3+4, 3+6, 3+9, 3/9, 3+9+15, 4x4, 5/8/14, 7x2,7x3, 7x4, 7x7, 7x12 and 7x19. Representative cord constructions with aspiral wrap include 2+1, 3+1, 5+1, 6+1, 7+1, 8+1, 11+1, 12+1, 1+4+1,1+5+1, 1+6+1, 1/6+1, 1+7+1, 1+8+1, 1+14+1, 1+15+1, 1+16+1, 1+17+1,1+18+1, 1+19+1, 1+20+1, 1+26+1, 2+7+1, 2+8+1, 2+9+1, 2+10+1, 3+9+1,3/9+1, 3+9+15+1, 7x2+1, 7x12+1, 7x19+1 and 27+1.

[0039] The cords listed above are particularly suited for use in apneumatic tire. The pneumatic tire may be a bias or radial ply tire.When used in the carcass ply, the preferred cords are 2x, 3x, 4x, 5x,6x, 8x, 11x, 12x, 1+2, 1+3, 1+4, 1+5, 1+6, 1+7, 1+8, 1+14, 1+15, 1+16,1+17, 1+18, 1+19, 1+20, 2+1, 2+7, 2+8, 2+9, 2+10, 2/2, 2/3, 2/4, 2/5,2/6, 3+1, 3+2, 3+3, 3+4, 3+9, 3/9, 3+9+15, 5/8/14, 7x12, 7x19, 5+1, 6+1,7+1, 8+1, 11+1, 12+1, 2+7+1, 1+4+1, 1+5+1, 1+6+1, 1+7+1, 1+8+1, 1+14+1,1+15+1, 1+16+1, 1+17+1, 1+18+1, 1+19+1, 1+20+1, 3+9+1, 3/9+1, 7x12+1 and7x19+1.

[0040] When the cords of the present invention are used in a beltstructure, the preferred cords are 2x, 3x, 4x, 5x, 6x, 8x, 11x, 12x,1+2, 1+3, 1+4, 1+5, 1+6, 1+7, 1+8, 1+14, 2+2, 2+5, 2+6, 2+7, 2+8, 2+9,2+10, 2+2+8, 2/2, 2/3, 2/4, 2/5, 2/6, 3+2, 3+3, 3+4, 3+6, 3+9, 3+9+15,27x, 1+26, 4x4, 5/8/14, 7x2, 12+1, 3+9+1, 1+6+1, 2+6+1, 2+7+1, 2+8+1,2+9+1, 2+10+1, 2+2+8+1, 3+9+15+1, 27+1, 1+26+1 and 7x2+1.

[0041] The filaments which may be used to make the cords of the presentinvention may have a diameter ranging from 0.10 mm to 0.45 mm.Preferably, the diameter of the filament ranges from 0.14 to 0.43 mm. Aparticularly preferred filament ranges from 0.18 to 0.38 mm.

[0042] According to the invention, a pneumatic off-the-road tire of 36inch and greater bead diameter with a carcass having cords, twosidewalls spaced apart a distance, which in the axial directiondetermines the general width of the tire section, two beads around eachone of which are turned up the ends of the cords of the carcass, a treaddisposed on the crown of the carcass, and a belt structurecircumferentially disposed between the tread and the carcass isdisclosed. The belt structure has a width that is substantially equal tothat of the tread and has at least one layer of elastomeric fabricreinforced with metallic cords. The metallic cords of the presentinvention are used in at least one layer such as a 7x19x0.20+1construction. In another embodiment, a pneumatic off-the-road tireincorporates metallic cords of the present invention in a 7x12x0.22+1construction. In a third embodiment, a pneumatic off-the-road tireincorporates metallic cords of the present invention having a7x12x0.25+1 construction.

[0043] There are a number of embodiments of metallic cord constructionof the present invention for the plies including 1x0.18, 2x0.18, 3x0.18.Also, according to the invention, the cords of the ply can beconstructed of 1+5x0.18. The tire can also include a ply having a cordof 1x0.24/6x0.22+1 or 1x0.18/6x0.16+1 construction.

[0044] According to the invention, the pneumatic radial tire describedbefore can include a belt structure of elastomeric fabric reinforcedwith metallic cords where the metallic cords are parallel to each andcomposed of filaments of ultra tensile steel. In one embodiment, thebelt structure includes first and second overlapped belts wherein thecords of the first and second belts are constructed of cords of thepresent invention having various configurations including, 2+2x0.30,2+2x0.35, 2x0.30, 2x0.35, 2+2x0.30, 2x0.23, 2x0.30, 3+2x0.33 and3+4x0.38.

[0045] In another embodiment of the former tire, the belt structureincludes first, second, third and fourth radially overlapped beltswherein the cords of the present invention used in the first and fourthbelt are constructed of 3+2x0.33 and the cords of the present inventionused in each of the second and third belts, sandwiched between the firstand fourth belts are constructed of 3+3x0.33. This tire also includes aply having a cord of the present invention in a 3x0.22/9x0.20+1construction. In still another embodiment, the belt structure includesfirst, second, third and fourth radially overlapped belts wherein thecords of each of the present invention are used in each of the first andfourth belts are constructed of 3+4x0.38 and the ply has a cord of3x0.22/9x0.20+1.

[0046] Further, many of the above described novel cords result in lowerlinear density in the reinforcement for which they are used which againresults in less weight and lower cost for the reinforcement and itsproduct, be it the tire, the belt or any other reinforced elastomeric.

[0047] Referring to FIGS. 1 and 2 of the drawings, plies 12 and 14 areshown within a pneumatic tire 10 with a radial carcass wherein likeelements have received like reference numerals. For the purposes of thepresent invention, a tire has a radial ply carcass structure when thecords of the carcass reinforcing ply, or plies 12,14 are oriented atangles in the range of 75° to 90° with respect to the equatorial plane(EP) of the tire.

[0048] In the instance where the metallic cords of the present inventionare used to reinforce the carcass, only one of the two plies, if two areused, should be so reinforced. The other ply should be reinforced withsome other form of reinforcement. It is preferred that, if two carcassplies are used, the metallic cord reinforced ply be the bottom (inner)carcass ply 14. Representative examples of reinforcement that can beused in the other non-metallic reinforced carcass ply is rayon,polyester and nylon.

[0049] The metallic cord reinforced carcass ply 12 has a layer of steelcords 30 arranged so as to have from about 8 to about 20 ends per inch(EPI) when measured in a tire circumferential direction at a locationhaving a tire maximum width (MW). Preferably, the layer of steel cords30 are arranged so as to have about 12 to about 16 ends per inch (EPI)at the location having a tire maximum width MW. In terms of metricunits, the steel cords are arranged as to have from 3 to 8 ends per cm(EPC) when measured in a tire circumferential direction at a locationhaving a tire maximum width. Preferably, the EPC ranges from 4 to 7 EPI.The above calculations for ends per inch are based upon the range ofdiameters or the overall cords, strength of the filaments and cords aswell as the required strength requirement for the single carcass ply.For example, the high number of ends per inch would include the use of alower diameter wire for a given strength versus a lower number of endsper inch for a lower diameter wire for the same strength. In thealternative, if one elects to use a monofilament of a given diameter,one may have to use more or less ends per inch depending on the strengthof the wire.

[0050] The tire 10 has a pair of substantially inextensible annularbeads 16,18 which are axially spaced apart from one another. Each of thebeads 16,18 is located in a bead portion of the tire 10 which hasexterior surfaces configured to be complimentary to the bead seats andretaining flanges of a rim (not shown) upon which the tire 10 isdesigned to be mounted. Plies 12,14 may be of side-by-side reinforcingcords of polyester or other material, or steel cord of the presentinvention and extend between the beads 16,18 with an axially outerportion of the carcass structure folded about each of the beads. Whilein the embodiment of FIG. 1, the carcass ply structure comprises twoplies 12,14 of reinforcing material, it is understood that one or morecarcass plies of any suitable material may be employed in certainembodiments and one or more plies of reinforcement according to thisinvention may be used as well.

[0051] A layer of a low permeability material 20 may be disposedinwardly of the carcass plies 12,14, and contiguous to an inflationchamber defined by the tire and rim assembly. Elastomeric sidewalls22,24 are disposed axially outwardly of the carcass structure. Acircumferentially extending belt structure 26 comprising in theembodiments shown two layers of belts 28,30 (FIG. 1), or four layers ofbelts 28,30,32,34 (FIG. 2), each of which preferably includes steelreinforcing cords 36 as shown in FIG. 3. The belt structure 26 of FIG. 2is characterized by the cords 36 having filaments with a tensilestrength of at least 4000 MPA [N/mm²] (called “ultra tensile” herein)for filaments with a 0.20 mm diameter. For example, cord 36, as shown inFIG. 3, has four filaments 38, 40, 42 and 44 (38-44) of ultra tensilesteel wire. While two and four layer belts are illustrated in FIGS. 1and 2, respectively, other numbers of belts can be substituted.

[0052] It will be appreciated that other laminates can be formed usingprinciples of the present invention for reinforcing other articles suchas industrial belts and that a single ply of the present invention canbe used with known or conventional plies to also form new usefulreinforced composite structures.

[0053] In a working example, the cords 36 are comprised of fourfilaments 38-44 of finely drawn, ultra tensile steel wire. There are anumber of metallurgical embodiments which result in the tensile strengthdefined above, i.e. at least 4000 MPA, as ultra tensile (UT). One way ofachieving UT strength is by merging the proper process as disclosed inU.S. Pat. No. No. 4,960,473, which is hereby incorporated by referencein its entirety herein, with a carbon rod microalloyed with one or moreof the following elements: Cr, Si, Mn, Ni, Cu, V and B. The preferredchemistry is listed below: C 0.88 to 1.0 Mn 0.30 to 0.50 Si 0.10 to 0.3Cr 0.10 to 0.4 V 0 to 0.1 Cu 0 to 0.5 Ni 0 to 0.5 Co 0.2 to 0.1 thebalance being iron and residuals

[0054] The resulting rod is then drawn to a tensile strength equivalentto 4000 Mpa @ 0.20 mm.

[0055] TABLE 1 below gives calculated strength level description forultra tensile filaments in comparison to previous high and super tensilesteel filaments having a filament diameter of 0.20 mm. The ultra tensilesteel has a higher value than any previously used steel cord orfilament. TABLE 1 HIGH TENSILE, SUPER TENSILE & ULTRA TENSILE STEEL CORDStrength Level Description High Super Tensile Tensile Ultra (HT) (ST)Tensile Rating  100  107  117 Tensile Strength 3400 3650 4000 (MPa) forfilament diameter (D) Tensile Strength −1400xD + −2000xD + −2000xD +(MPa) for filament 3680 4050 4400 diameter (D)

[0056] The cords 36 used in the working example, as shown in FIG. 3,have a structure of four filaments 38, 40, 42 and 44 typically of 0.30mm or 0.35 mm diameter ultra tensile steel wire with a cord breakingstrength of at least 1,020 Newtons, plus or minus 5.0 percent. Each cord36 has two filaments 38, 40 twisted together with a 16 mm lay length andthese two filaments 38,40 are then twisted at a 16 mm lay lengthtogether in the same twist direction with the remaining two filaments42,44 which are untwisted and parallel to each other when twistedtogether with the twisted filaments 38,40. This cord, commonly called a2+2 construction is designated as 2+2x0.30 UT or 2+2x0.35 UT. The 2+2construction is known for its openness and good rubber penetrationresulting from the openness. The 0.30 and 0.35 designates the filamentdiameter in millimeters and the UT designates the material being ultratensile steel. TABLE 2 Ultra Tensile Cord Former Cord StructureStructure Max Max Cord Gauge Cord Gauge Structure (mm) Structure (mm)Radial Passenger and Light Truck Belts 1) 2x.30 HT .60 2x.23 UT 0.46Radial Light Truck Belts 2) 2 + 2x.30 HT .90 2x.30 UT 0.60 3) 2 + 2x.30HT .90 2x.35 UT 0.70 Radial Medium Truck Belts 4) 2 + 2x.35 ST 1.05 2 +2x.30 UT 0.90 1.05 2 + 2x.33 UT 0.99 1.05 2 + 2x.35 UT 1.05 5) 3 + 2x.35ST 1.05 3 + 2x.30 UT 0.90 1.05 3 + 2x.33 UT 0.99 1.05 3 + 2x.35 UT 1.056) 3 + 3x.35 ST 1.05 3 + 3x.30 UT 0.90 1.05 3 + 3x.33 UT 0.95 1.05 3 +3x.35 UT 1.05 7) N + MxD ST¹ N + Mx.30 UT 0.90 N + Mx.33 UT 0.95 N +Mx.35 UT 1.05

[0057] Above in TABLE 2 are other embodiments of ultra tensile cordmatched for comparison with the former tire cord, e.g., high tensile(HT) and super tensile (ST) steel cords which it replaced, the aboveexample cord 36 being listed as 2 and 3. The illustrated examples ofultra tensile cord structure, candidates 1 and candidates 2, 3 and 4above in TABLE 2, are shown in FIGS. 5 and 3, respectively, and show areduction in cord gauge as compared with the corresponding former cordstructures of the three candidates. When the new cord structuresincorporate filaments having a smaller diameter than those of thepreviously noted corresponding former cord structures, there is aresulting reduction in gauge material and cost as compared with theformer cord structures making the tires lighter in weight and lesscostly.

[0058] For equal filament diameters, the ultra tensile cords have higherstrength and generally higher fatigue life over the predecessor high andsuper tensile cords. These advantages lead to elastomer products whichhave less reinforcement material and thus lower weight and cost.Further, the life of the product can be increased with the increase infatigue life of the cord and its filaments.

[0059] In a similar manner, the illustrated examples of ultra tensilecord structure, candidates 5 and 6 above in TABLE 2, are shown in FIGS.7 and 8, respectively, and show a reduction in cord gauge as comparedwith the two mentioned corresponding former cord structures. Further,the new cord structures of small diameter filaments reduce gaugematerial and cost as compared with the previously noted former cordstructures making the tires lighter in weight and less costly.

[0060] The following TABLE 3 shows other embodiments of ultra tensileply structures matched for comparison with the former ply structureswhich they replace. Some former plies incorporate polyester or hightensile (HT) steel. TABLE 3 Ultra Tensile Ply Former Ply StructureStructure Max Max Cord Cord Gauge Gauge Structure (mm) Structure (mm)Radial Passenger and Light Truck Plies 1) 1100/3 .66 2x.18 UT .36polyester single ply 2) 1100/2 .56 3x.18 UT .36 polyester two ply RadialLight Truck Plies 3) 1440/3 .76 1 + 5x.18 UT .54 polyester with and twoply without wrap Radial Medium Truck Belts 4) 27x.175 HT 1.053x.22/9x.20 + 1 UT .84 5) 3x.22/9x.20 + 1 HT .84 2 + 7x.22 + 1 UT .88 6)3x.22/9x.20 + 1 HT .84 1x.24 + 6x.22 + 1 UT .68 7) 3x.22/9x.20 + 1 HT.84 1x.24 + 6x.22 UT .68 Off-The-Road Plies 8) 7x19x.20 + 1 HT 3.007x19x.20 + 1 UT 3.00 9) 7x19x.20 + 1 HT 3.00 7x12x.22 + 1 UT 2.34 10)7x19x.20 + 1 HT 3.00 7x12x.25 + 1 UT 3.02

[0061] Candidates 1 and 2 above in TABLE 3 and illustrated in FIGS. 5and 10, show a replacement of polyester ply with steel ply. The plystructures incorporating UT steel filaments are stronger and reduce thegauge and cost of the material, as compared with the previously notedformer polyester ply structures making the tires lighter in weight andless costly.

[0062] Candidate 3, above in TABLE 3, is related to radial light truckplies and is illustrated in FIG. 11, shows a replacement of polyesterply with steel ply.

[0063] Further, Candidates 4, 5, 6 and 7 above in TABLE 3, are relatedto radial medium truck plies and are illustrated in FIGS. 14, 12 and 13.These candidates show a replacement of high tensile ply configurationswith ultra tensile steel ply configurations. The ply structures of UTsteel filaments are stronger and reduce gauge material and cost ascompared with the previously noted former high tensile ply structuresmaking the tires lighter in weight and less costly.

[0064] Candidates 8, 9 and 10 above in TABLE 3, are related tooff-the-road plies as illustrated in FIGS. 15 and 16. These candidatesshow a replacement of a high tensile ply configuration, as shown in FIG.15, with the corresponding ultra tensile steel ply configurations ofFIGS. 15 and 16. As in the previous cases, the ply structures of UTsteel filaments are stronger and reduce gauge material and cost ascompared with the previously noted former high tensile ply structuresmaking the tires lighter in weight and less costly.

[0065] TABLE 4 below compares the current construction together with abenefit analysis of P195/75R14 passenger tires of two belts, as shown inFIG. 1 and depicted in FIG. 4, wherein the current two layer beltsincorporate high tensile cable configurations and the disclosed twolayer belts of the new construction incorporate ultra tensile cableconfigurations. Three candidates of ultra tensile construction aredescribed with (a) equal strength, lower tire gauge, higher EPI andlower tire weight in candidate 1; (b) equal strength, identical tiregauge, lower EPI and less tire weight in candidate 2; and (c) increasedstrength, equal tire gauge, equal EPI and equal tire weight in candidate3.

[0066] With candidate 1, when the diameter of the filaments wasdecreased from 0.30 mm high tensile to 0.23 mm ultra tensile, the EPIincreased. Nevertheless, an equal strength was achieved with a lowertire gauge and significant savings in tire weight. With candidate 2,when the diameter of the filaments was held constant at 0.30 mm, thereplacement of high tensile steel with ultra tensile steel resulted in adecrease in EPI and a lower weight tire of equal strength. Withcandidate 3, the replacement of high tensile steel with ultra tensilesteel, while keeping the tire gauge and the EPI constant, resulted in atire with the same weight and gauge, but with an approximate 16 percentincrease in strength. TABLE 4 ULTRA TENSILE STEEL CORD BENEFITS BELTS -PASSENGER TIRES P195/75R14 Current Belt Structure Ultra Tensile BeltStructure Construction EPI Construction EPI Benefits 1) Belt 1 2x.30 HT24 2x.23 UT 34 Equal Strength Belt 2 2x.30 HT 24 2x.23 UT 34 Lower TireWeight Gauge 0.096 in Gauge 0.080 in (0.5 lbs lower) Weight 3.2 lbsWeight 2.7 lbs Lower Tire Gauge 2) Belt 1 2x.30 HT 24 2x.30 UT 20.5Equal Strength Belt 2 2x.30 HT 24 2x.30 UT 20.5 Lower Tire Weight Gauge0.096 in Gauge 0.096 in (0.20 lbs lower) Weight 3.2 lbs Weight 3.0 lbs3) Belt 1 2x.30 HT 24 2x.30 UT 24 16% Increased Belt 2 2x.30 HT 24 2x.30UT 24 Strength Gauge 0.096 in Gauge 0.096 in Weight 3.2 lbs Weight 3.2lbs

[0067] TABLE 5 below compares the current construction together with abenefit analysis of LT215/85R16 LR-C light truck tires of two belts, asshown in FIG. 1 and depicted in TABLE 5. The current belt structureincorporates two layered belts of 2+2 high tensile cable configurationsand the newly disclosed two layer belts incorporate ultra tensile cableconfigurations. Two candidates of ultra tensile construction with (a)equal strength, lower tire gauge, higher EPI and lower tire weight incandidate 1; and (b) equal strength, lower tire gauge, higher EPI andlower tire weight in candidate 2.

[0068] With candidate 1, the 2+2x0.30 HT configuration of Belt 1 wasreplaced with a simpler 2x0.30 UT configuration and the 2+2x0.30 HTconfiguration of Belt 2 was replaced with a simpler 2x0.23 UTconfiguration. In each case, the EPI increased. Nevertheless, an equalstrength was achieved with a significant savings in tire weight and alower tire gauge. With candidate 2, the 2+2x0.30 HT configurations ofBelt 1 and Belt 2 were each replaced with a simpler 2x0.35 UTconfiguration. In each case, the EPI increased. Nevertheless, an equalstrength was achieved with a significant savings in tire weight and alower tire gauge. TABLE 5 ULTRA TENSILE STEEL CORD BENEFITS BELTS -RADIAL LIGHT TRUCK TIRES LT215/85R16 LR-C Current Belt Structure UltraTensile Belt Structure Construction EPI Construction EPI Benefits 1)Belt 1 2 + 2x.30 HT 13 2x.30 UT 22 Equal Strength Belt 2 2 + 2x.30 HT 132x.30 UT 22 Lower Tire Weight Gauge 0.112 in Gauge 0.092 in (0.7 lbslower) Weight 4.8 lbs Weight 4.1 lbs Lower Tire Gauge 2) Belt 1 2 +2x.30 HT 13 2x.35 UT 17 Equal Strength Belt 2 2 + 2x.30 HT 13 2x.35 UT17 Lower Tire Weight Gauge 0.112 in Gauge 0.100 in (0.4 lbs lower)Weight 4.8 lbs Weight 4.4 lbs Lower Tire Gauge

[0069] Another comparison of high tensile and ultra-tensile cord isgiven in TABLE 5 where two current high tensile belt structures arecompared with two candidates of ultra-tensile belt structures inLT215/85R1G LR-C radial light truck tires. These tires incorporated twobelts with 2+2 type construction in the current models and a simple2x0.30, 2x0.23 or 2x0.35 cord in the ultra-tensile models. Inconstruction 1, to achieve equal strength between the current hightensile and the ultra-tensile examples, the EPI increased, the tiregauge was lower and a lower tire weight was achieved. In construction 2,the ultra-tensile filaments had a larger diameter and the EPI increasedto maintain an equal strength. At the same time, both the tire gauge andthe tire weight was lower.

[0070] TABLE 6 below compares the current construction together with abenefit analysis of LT215/85R16 LR-D radial light truck tires of twobelts, as shown in FIG. 1. The current belt structure incorporates twolayered belts of 2+2 high tensile cable configurations and the newlydisclosed two layered belts which incorporates ultra tensile cableconfigurations. Three candidates of ultra tensile construction with (a)equal strength, lower tire gauge, higher EPI and lower tire weight incandidate 1; (b) equal strength, equal tire gauge, lower EPI and lowertire weight in candidate 2; and (c) higher strength, equal tire gauge,equal EPI and equal tire weight in candidate 3.

[0071] With candidate 1, the 2+2x0.30 HT configuration of Belts 1 and 2were both replaced with a simpler 2x0.35 UT configuration. In each case,the EPI increased. Nevertheless, an equal strength was achieved with asignificant savings in tire weight and a lower tire gauge. Withcandidate 2, the 2+2x0.30 HT configurations of Belt 1 and Belt 2 wereeach replaced with 2+2x0.30 UT configurations. In each case, the EPIdecreased while maintaining an equal strength, an equal tire gauge and areduction in tire weight. With candidate 3, the 2+2x0.30 HTconfigurations of Belt 1 and Belt 2 were again replaced with 2+2x0.30 UTconfigurations. However, in each case, the EPI remained the same. Theresult was a significantly increased strength, while the tire gauge andthe tire weight remained the same. TABLE 6 ULTRA TENSILE STEEL CORDBENEFITS BELTS - RADIAL LIGHT TRUCK TIRES LT215/85R16 LR-D Current BeltStructure Ultra Tensile Belt Structure LR-D Construction EPIConstruction EPI Benefits 1) Belt 1 2 + 2x.30 HT 17 2x.35 UT 22 EqualStrength Belt 2 2 + 2x.30 HT 17 2x.35 UT 22 Lower Tire Weight Gauge0.112 in Gauge 0.100 in (0.4 lbs lower) Weight 5.1 lbs Weight 4.7 lbsLower Tire Gauge 2) Belt 1 2 + 2x.30 HT 17 2 + 2x.30 UT 14.5 EqualStrength Belt 2 2 + 2x.30 HT 17 2 + 2x.30 UT 14.5 Lower Tire WeightGauge 0.112 in Gauge 0.112 in (.2 lbs lower) Weight 5.1 lbs Weight 4.9lbs 3) Belt 1 2 + 2x.30 HT 17 2 + 2x.30 UT 17 16% Increased Belt 2 2 +2x.30 HT 17 2 + 2x.30 UT 17 Strength Gauge 0.112 in Gauge 0.112 inWeight 5.1 lbs Weight 5.1 lbs

[0072] TABLE 7 below compares the current construction together with abenefit analysis of LT235/85R16 LR-E light truck tires of two belts, asshown in FIG. 1 and depicted in TABLE 7. The current belt structureincorporates two layered belts of 2+2 super tensile cable configurationsand the newly disclosed two layer belts incorporates ultra tensile cableconfigurations. Three candidates of ultra tensile construction with (a)equal strength, lower tire gauge, higher EPI and lower tire weight incandidate 1; (b) equal strength, equal tire gauge, lower EPI and lowertire weight in candidate 2; and (c) higher strength, equal tire gauge,equal EPI and equal tire weight in candidate 3.

[0073] With candidate 1, the 2+2x0.35 ST configuration of Belts 1 and 2were both replaced with a 2+2x0.30 UT configuration. In each case, theEPI increased. Nevertheless, an equal strength was achieved with asignificant savings in tire weight and a lower tire gauge. Withcandidate 2, the 2+2x0.35 HT configurations of Belt 1 and Belt 2 wereeach replaced with 2+2x0.35 UT configurations. In each case, the EPIdecreased while maintaining an equal strength, an equal tire gauge and areduction in tire weight. With candidate 3, the 2+2x0.35 STconfigurations of Belt 1 and Belt 2 were again replaced with 2+2x0.35 UTconfigurations. However, in each case, the EPI remained the same. Theresult was an increased strength, while the tire gauge and the tireweight remained the same. TABLE 7 ULTRA TENSILE STEEL CORD BENEFITSBELTS - RADIAL LIGHT TRUCK TIRES LT235/85R16 LR-E Current Belt StructureUltra Tensile Belt Structure LR-E Construction EPI Construction EPIBenefits 1) Belt 1 2 + 2x.35 ST 17.5 2 + 2x.30 UT 21 Equal Strength Belt2 2 + 2x.35 ST 17.5 2 + 2x.30 UT 21 Lower Tire Weight Gauge 0.126 inGauge 0.114 in (0.6 lbs lower) Weight 7.2 lbs Weight 6.6 lbs Lower TireGauge 2) Belt 1 2 + 2x.35 ST 17.5 2 + 2x.35 UT 16 Equal Strength Belt 22 + 2x.35 ST 17.5 2 + 2x.35 UT 16 Lower Tire Weight Gauge 0.126 in Gauge0.126 in (0.3 lbs lower) Weight 7.2 lbs Weight 6.9 lbs 3) Belt 1 2 +2x.35 ST 17.5 2 + 2x.35 UT 17.5 12% Increased Belt 2 2 + 2x.35 ST 17.52 + 2x.35 UT 17.5 Strength Gauge 0.126 in Gauge 0.126 in Weight 7.2 lbsWeight 7.2 lbs

[0074] TABLE 8 below compares a current two-ply P225/P75R15 passengertire with an ultra tensile ply structure. With the candidate 1, equalstrength was achieved with lower tire gauge, an increase in EPI, and aslight increase in weight. With candidate 2, equal strength was achievedwith lower tire gauge, an equal EPI and a decrease in tire weight.

[0075] With candidate 1, the 1100/2 polyester configurations of Plies 1and 2 were replaced with 2x0.18 UT configuration. In this case, the EPIincreased while maintaining an equal strength, a lower tire gauge and alower tire weight. With candidate 2, the 1100/2 polyester configurationof Plies 1 and 2 were replaced with 3x0.18 UT configuration. In thiscase, the strength and EPI remained constant while achieving a lowertire gauge and a lower tire weight. TABLE 8 ULTRA TENSILE STEEL CORDBENEFITS PLY - PASSENGER TIRES P225/75R15 Current Belt Structure UltraTensile Belt Structure Two-Ply Construction EPI Construction EPIBenefits 1) Ply 1 1100/2 Poly 30 2x.18 UT 43 Equal Strength Ply 2 1100/2Poly 30 Lower Tire Weight Gauge 0.084 in Gauge 0.044 in (.8 lbs lower)Weight 3.4 lbs Weight 2.6 lbs Lower Tire Gauge 2) Ply 1 1100/2 Poly 303x.18 UT 30 Equal Strength Ply 2 1100/2 Poly 30 Lower Tire Weight Gauge0.084 in Gauge 0.044 in (.8 lbs lower) Weight 3.4 lbs Weight 2.6 lbsLower Tire Gauge

[0076] TABLE 9 compares a current two-ply polyester construction with anultra tensile construction in LT235/85R16 radial light truck tires of aload range E. Referring to the candidate, an equal strength wasmaintained while achieving lower tire weight and lower tire gauge. Whenthe 1440/3 polyester configuration of Plies 1 and 2 were replaced with1+5x0.18 UT configuration, the EPI slightly increased, and an equalstrength was achieved with a reduction in tire weight and tire gauge.TABLE 9 ULTRA TENSILE STEEL CORD BENEFITS PLY - RADIAL LIGHT TRUCK TIRESLT235/85R16 LR-E Current Belt Structure Ultra Tensile Belt StructureTwo-Ply Construction EPI Construction EPI Benefits 1) Ply 1 1440/3 Poly27 1 + 5x.18 UT 28 Equal Strength Ply 2 1440/3 Poly 27 Lower Tire WeightGauge 0.118 in Gauge 0.061 in (0.9 lbs lower) Weight 6.6 lbs Weight 5.7lbs Lower Tire Gauge

[0077] TABLE 10 below compares the current construction with a benefitanalysis of 11R24.5 LR-G radial medium truck tires of four belts, asshown in FIG. 2. With candidate 1, the current belt structure includesfour layered belts of 3+2 super tensile cable configurations and a plyof 3x0.22/9x0.20+1 high tensile cable. The new disclosed four layerbelts and single ply incorporates a 3+2x0.33 ultra tensile for each ofthe belts and a 1x0.24/6x0.22+1 UT for the ply. Note that the EPI ofbelts 1 and 4, and belts 2 and 3 remain the same for both the currentand new constructions while the EPI for the new ply increases. Thebenefits achieved by the use of the ultra tensile configurations is anincrease in the rivet of belts 2 and 3, a tire weight reduction, a tirecost reduction and improved corrosion resistance in the ply.

[0078] Referring to candidate 2, the belts of the current configurationswere replaced by belts with a 3+4x0.38 UT configuration and an EPI whichis lower than that in the current belts. The 3x0.22/9x0.20+1 HT cableconfiguration in the ply is replaced by a 1x0.24/6x0.22+1 UT cableconfiguration in the ply. The advantage of the configurations ofcandidate 2 is a significant increase in the rivet of belts 2 and 3, atire weight reduction, a tire cost reduction, improved corrosionresistance in the ply and single belt wire construction which isapplicable to all of the load ranges for the radial medium truck tires.TABLE 10 ULTRA TENSILE STEEL BENEFITS RADIAL MEDIUM TRUCK TIRES 11R24.5LR-G Current Belt Structure Ultra Tensile Belt Structure ConstructionEPI Construction EPI Benefits 1) Belt 1 3 + 2x.35 ST 10 3 + 2x.33 UT 10Rivet increased 7% in belts 2 and 3. Belt 2 3 + 2x.35 ST 14 3 + 2x.33 UT14 Tire weight reduced by 2.8 lbs. Belt 3 3 + 2x.35 ST 14 3 + 2x.33 UT14 Tire cost reduced. Belt 4 3 + 2x.35 ST 10 3 + 2x.33 UT 10 Improvedcorrosion resistance in ply. Ply 3x.22/9x.20 + 1 HT 16 1x.24/6x.22 + 1UT 20 2) Belt 1 3 + 2x.35 ST 10 3 + 4x.38 UT 09 Rivet increased 224% inbelts 2 and 3. Belt 2 3 + 2x.35 ST 14 3 + 4x.38 UT 09 Tire weightreduced 0.7 lbs. Belt 3 3 + 2x.35 ST 14 3 + 4x.38 UT 09 Tire costreduced. Belt 4 3 + 2x.35 ST 10 3 + 4x.38 UT 09 Improved corrosionresistance in ply. Ply 3x.22/9x.20 + 1 HT 16 1x.24/6x.22 + 1 UT 20 Onebelt wire construction applicable to all load ranges.

[0079] TABLE 11 below compares the current construction with a benefitanalysis of 11R24.5 LR-H radial medium truck tires of four belts, asshown in FIG. 2. With candidate 1, the current belt structure includesfour layered belts of 3+2 and 3+3 super tensile cable configurations anda ply of 3/9/15x0.175+1 HT cable. The newly disclosed four layer beltsand single ply incorporates a 3+2x0.33 UT for belts 1 and 4, a 3+3x0.33UT for belts 2 and 3 and a 3x0.22/9x0.20+1 UT for the ply. Note that theEPI of belts 1 and 4 and belts 2 and 3 remain the same for both thecurrent and new constructions while the EPI for the new ply constructionincreases. The benefits achieved by the use of the ultra tensileconfigurations is an increase in the rivet of belts 2 and 3, a tireweight reduction and a tire cost reduction.

[0080] Referring to candidate 2, the belts of the current configurationswere replaced by belts with a 3+4x0.38 UT configuration and an EPI whichis lower than that in the current belts. The 3/9/15x0.175+1 HT cableconfiguration in the ply is replaced by a 3x0.22/9x0.20+1 UT cableconfiguration in the ply. The advantage of the configurations ofcandidate 2 is a significant increase in the rivet of belts 2 and 3, atire weight reduction, a tire cost reduction and single belt wireconstruction which is applicable to all of the load ranges for theradial medium truck tires. TABLE 11 ULTRA TENSILE STEEL BENEFITS RADIALMEDIUM TRUCK TIRES 11R24.5 LR-H Current Belt Structure Ultra TensileBelt Structure Construction EPI Construction EPI Benefits 1) Belt 1 3 +2x.35 ST 10 3 + 2x.33 UT 10 Rivet increased 10% in belts 2 and 3. Belt 23 + 3x.35 ST 16 3 + 3x.33 UT 16 Tire weight reduced by 2.9 lbs. Belt 33 + 3x.35 ST 16 3 + 3x.33 UT 16 Tire cost reduced. Belt 4 3 + 2x.35 ST10 3 + 2x.33 UT 10 Ply 3/9/15x.175 + 1 HT 13 3x.22/9x.20 + 1 UT 19 2)Belt 1 3 + 2x.35 ST 10 3 + 4x.38 UT 09 Rivet increased 225% in belts 2and 3. Belt 2 3 + 3x.35 ST 16 3 + 4x.38 UT 11 Tire weight reduced 1.6lbs. Belt 3 3 + 3x.35 ST 16 3 + 4x.38 UT 11 Tire cost reduced. Belt 43 + 2x.35 ST 10 3 + 4x.38 UT 09 One belt wire construction applicable toall load ranges. Ply 3/9/15x.175 + 1 HT 13 3x.22/9x.20 + 1 UT 19

[0081] By utilizing ultra tensile steel filament of at least 4000 MPa ata 0.20 mm diameter, several options become available in steel corddesign for Off-The-Road (OTR) pneumatic tires, as described in TABLE 12below. Utilization of the higher tensile strength materials combinedwith simplification and/or variations of current steel cord constructionwill satisfy the OTR tire requirements of higher inch strength whileincreasing the rivet area between cords. For example, the steel cordcable construction currently used for ply reinforcement in OTR tires forsizes 36.00R51 and larger is 7x0.19x0.20+1 HT, as shown in TABLES 3 and13. The filament tensile strength is specified as 3300 MPa at 0.20 mmfilament diameter. The average cable breaking load is 11,600 N and isused at 6.4 ends/inch thus giving an inch strength of 74,240 N whichsatisfies the design requirement of 73,975 N. The cable gauge of 3.0 mmyields a rivet of 0.965 mm.

[0082] A major design parameter which may be varied in a reinforcedcomposite of elastomer is the end count in end per inch (EPI), i.e., thenumber of cords per unit length in the lateral direction to thedirection in which the elastomer is being reinforced. TABLE 12 belowlists examples of a current high tensile construction and possible ultratensile constructions, see candidates 1-3 and FIGS. 15 and 16, showingthe general increase in rivet as the increased strength of the ultratensile samples allowed a reduction in EPI. At the other extreme, ascord diameter is reduced and the end count increased to off-set it, therivet is reduced. Generally, a minimum rivet of 0.018″ (0.46 mm) must bemaintained to give proper penetration of elastomers between cords whenthey are so embedded. This minimum rivet is particularly obtainable withthe smaller diameter and simpler (less filaments in a cord) cordconstruction of candidates 1, 2 and 3. TABLE 13 Break Inch- Gauge LoadStretch Rivet Construction (mm) (N) EPI (N) (mm) Current Construction7x19x.20 + 1 HT 3.0  11,600 6.4 74,240 .965 Ultra TensileConstruction 1. 7x19x.20 + 1 UT 3.0  13,570 5.5 74,630 1.62 2.7x12x.22 + 1 UT 2.34 10,500 7.1 74,550 1.24 3. 7x12x.25 + 1 UT 3.0213,000 5.7 74,100 1.44

[0083] Candidates 1, 2 and 3 satisfy the tire design requirements of74,240 N inch-strength for 36.00R51 through 40.00R57 OTR tires whileproviding increased rivet in all cases (greater than 0.96 mm). Thisincreased rivet allows more rubber penetration between cords givinggreater strike-through. In addition, candidate 1, when used at 6.4 EPI(not shown), has a rivet area between cords of 0.965 mm (as with thecurrent construction) while providing an inch-strength of 83,200 N. Thisvalue of inch-strength exceeds the requirement of 79,800 N/inch for anew, larger 44.00R57 OTR tire.

[0084] It is apparent that there has been provided, in accordance withthis invention, a strip of ply stock reinforced with steel monofilamentsor cords for use in a tire. The strip of reinforced, ply stock satisfiesthe objects, means and advantages set forth hereinbefore.

[0085] While the invention has been described in combination withembodiments thereof, it is evident that many alternatives, modificationsand variations will be apparent to those skilled in the art in light ofthe foregoing description. Accordingly, it is intended to embrace allsuch alternatives, modifications and variations as fall within thespirit and scope of the appended claims.

What is claimed is:
 1. A cord for reinforcing elastomer articles ofmultiple filaments having a diameter (D) range of 0.10 to 0.45 mm, eachfilament having at least a tensile strength of −2000×D+4400 MPa, where Dis the filament diameter in mm.
 2. The cord defined in claim 1 wherein Dranges from 0.14 to 0.42 mm.
 3. The cord defined in claim 1 wherein thecord construction is selected from the group consisting of 2x, 3x, 4x,5x, 6x, 7x, 8x, 11x, 12x, 27x, 1+2, 1+3, 1+4, 1+5, 1+6, 1+7, 1+8, 1+14,1+15, 1+16, 1+17, 1+18, 1+19, 1+20, 1+26, 2+1, 2+2, 2+5, 2+6, 2+7, 2+8,2+9, 2+10, 2/2, 2/3, 2/4, 2/5, 2/6, 3+1, 3+2, 3+3, 3+4, 3+6, 3+9, 3/9,3+9+15, 4x4, 5/8/14, 7x2, 7x3, 7x4, 7x7, 7x12, 7x19, 5+1, 6+1, 7+1, 8+1,11+1, 12+1, 2+7+1, 1+4+1, 1+5+1, 1+6+1, 1+7+1, 1+8+1, 1+14+1, 1+15+1,1+16+1, 1+17+1, 1+18+1, 1+19+1, 1+20+1, 2+2+8, 2+6+1, 2+7+1, 2+8+1,2+9+1, 2+10+1, 2+2+8+1, 3+9+15+1, 27+1, 1+26+1, 7x2+1, 3+9+1, 3/9+1,7x12+1 and 7x19+1.
 4. The cord defined in claim 1 wherein D ranges from0.18 to 0.38 mm.
 5. The cord defined in claim 3, wherein the cordconstruction is selected from the group consisting of 7x19x0.20, 2x0.18,2+2x0.30, 2+2x0.35, 2x0.30, 2x0.35, 2+2x0.30, 2x0.23, 3+2x0.33,3+4x0.38, 3+2x0.33, 3+3x0.33, 1x0.24/6x0.22+1, 1x0.18/6x0.16+1,3+4x0.38, 3x0.22/9x0.20+1 and 2+7x0.22+1.
 6. A cord defined in claim 3wherein said cord construction is selected from the group consisting of2x, 3x, 4x, 5x, 6x, 8x, 11x, 12x, 1+2, 1+3, 1+4, 1+5, 1+6, 1+7, 1+8,1+14, 1+15, 1+16, 1+17, 1+18, 1+19, 1+20, 2+1, 2+7, 2+8, 2+9, 2+10, 2/2,2/3, 2/4, 2/5, 2/6, 3+1, 3+2, 3+3, 3+4, 3+9, 3/9, 3+9+15, 5/8/14, 7x12,7x19, 5+1, 6+1, 7+1, 8+1, 11+1, 12+1, 2+7+1, 1+4+1, 1+5+1, 1+6+1, 1+7+1,1+8+1, 1+14+1, 1+15+1, 1+16+1, 1+17+1, 1+18+1, 1+19+1, 1+20+1, 3+9+1,3/9+1, 7x12+1 and 7x19+1.
 7. The cord defined in claim 3 wherein saidcord construction is selected from the group consisting of 2x, 3x, 4x,5x, 6x, 8x, 11x, 12x, 1+2, 1+3, 1+4, 1+5, 1+6, 1+7, 1+8, 1+14, 2+2, 2+5,2+6, 2+7, 2+8, 2+9, 2+10, 2+2+8, 2/2, 2/3, 2/4, 2/5, 2/6, 3+2, 3+3, 3+4,3+6, 3+9, 3+9+15, 27x, 1+26, 4x4, 5/8/14, 7x2, 12+1, 3+9+1, 1+6+1,2+6+1, 2+7+1, 2+8+1, 2+9+1, 2+10+1, 2+2+8+1, 3+9+15+1, 27+1, 1+26+1 and7x2+1.
 8. A pneumatic tire with a carcass having parallel cords, twosidewalls spaced apart a distance, which in the axial directiondetermines the general width of the tire section, two beads each one ofwhich around which are turned up, from the inside toward the outside,the ends of the cords of the carcass, a tread disposed on the crown ofsaid carcass, a belt structure that is circumferentially inextensibleinterposed between the tread and the carcass, and carcass plies disposedin said sidewalls between said two beads and said crown of said carcass,said belt structure having a width that is substantially equal to thatof the tread and having carcass plies of elastomeric fabric reinforcedwith metallic cords, said metallic cords being comprised of a pluralityof filaments having a diameter (D) ranging from 0.10 to 0.45 mm, eachfilament having a tensile strength of −2000×D+4400 MPa, where D is thefilament diameter in mm.
 9. The pneumatic tire defined in claim 8wherein D ranges from 0.14 to 0.42 mm.
 10. The pneumatic tire defined inclaim 8 wherein the cord construction is selected from the groupconsisting of 2x, 3x, 4x, 5x, 6x, 7x, 8x, 11x, 12x, 27x, 1+2, 1+3, 1+4,1+5, 1+6, 1+7, 1+8, 1+14, 1+15, 1+16, 1+17, 1+18, 1+19, 1+20, 1+26, 2+1,2+2, 2+5, 2+6, 2+7, 2+8, 2+9, 2+10, 2/2, 2/3, 2/4, 2/5, 2/6, 3+1, 3+2,3+3, 3+4, 3+9, 3/9, 3+9+15, 5/8/14, 7x2, 7x19, 7x2, 5+1, 6+1, 7+1, 8+1,11+1, 12+1, 2+7+1, 1+4+1, 1+5+1, 1+6+1, 1+7+1, 1+8+1, 1+14+1, 1+15+1,1+16+1, 1+17+1, 1+18+1, 1+19+1, 1+20+1, 3+9+1, 3/9+1, 7x12+1 and 7x19+1.11. The pneumatic tire defined in claim 10 wherein said cordconstruction is 1+5.
 12. A pneumatic tire with a carcass having parallelcords, two sidewalls spaced apart a distance, which in the axialdirection determines the general width of the tire section, two beadseach one of which around which are turned up, from the inside toward theoutside, the ends of the cords of the carcass, a tread disposed on thecrown of said carcass, a belt structure that is circumferentiallyinextensible interposed between the tread and the carcass, and carcassplies disposed in said sidewalls between said two beads and said crownof said carcass, said belt structure having a width that issubstantially equal to that of the tread and having at least one layerof elastomeric fabric reinforced with metallic cords, said metalliccords being comprised of a plurality of filaments having a diameter (D)ranging from 0.10 to 0.45 mm, each filament having a tensile strength of−2000×D+4400 MPa, where D is the filament diameter in mm.
 13. Thepneumatic tire defined in claim 12 wherein D ranges from 0.14 to 0.42mm.
 14. The pneumatic tire defined in claim 12 wherein the cordconstruction is selected from the group consisting of 2x, 3x, 4x, 5x,6x, 7x, 8x, 11x, 12x, 27x, 1+2, 1+3, 1+4, 1+5, 1+6, 1+7, 1+8, 1+14,1+15, 1+16, 1+17, 1+18, 1+19, 1+20, 1+26, 2+2, 2+5, 2+6, 2+7, 2+8, 2+9,2+10, 2/2, 2/3, 2/4, 2/5, 2/6, 3+2, 3+3, 3+4, 3+9, 3+9+15, 27x, 1+26,5/8/14, 7x2, 12+1, 3+9+1, 1+6+1, 2+6+1, 2+7+1, 2+8+1, 2+9+1, 2+10+1,2+2+8+1, 3+9+15+1, 27+1, 1+26+1 and 7x2+1.
 15. The pneumatic tiredefined in claim 12 wherein said tire is an off-the-road tire of 36 inchand greater bead diameter with a carcass having cords, two sidewallsspaced apart a distance, which in the axial direction determines thegeneral width of the tire section, two beads each one of which aroundwhich are turned up the ends of the cords of the carcass, a treaddisposed on the crown of the carcass, and a belt structure that iscircumferentially disposed between the tread and the carcass, the beltstructure having a width that is substantially equal to that of thetread and having at least one layer of elastomeric fabric reinforcedwith metallic cords, said metallic cords in at least one layer being of7x19x0.20+1 construction with a gauge of 3.0 mm and a rivet of 1.62 mm.16. The pneumatic tire of claim 15 wherein the inch strength of said onelayer is 74,630 N.
 17. The pneumatic tire of claim 16 wherein the cordsare spaced at 5.5 EPI.
 18. The pneumatic tire of claim 12 wherein saidtire is an off-the-road tire of 36 inch and greater bead diameter with acarcass having cords, two sidewalls spaced apart a distance, which inthe axial direction determines the general width of the tire section,two beads each one of which around which are turned up the ends of thecords of the carcass, a tread disposed on the crown of the carcass, anda belt structure that is circumferentially disposed between the treadand the carcass, the belt structure having a width that is substantiallyequal to that of the tread and having at least one layer of elastomericfabric reinforced with metallic cords, said metallic cords in at leastone layer being of 7x12x0.22+1 construction with a gauge of 2.34 mm anda rivet of 1.24 mm.
 19. The pneumatic tire of claim 18 wherein the inchstrength of said one layer is 74,550 N.
 20. The pneumatic tire of claim19 wherein the cords are spaced at 7.1 EPI.
 21. The pneumatic tiredefined in claim 12 wherein said tire is an off-the-road tire of 36 inchand greater bead diameter with a carcass having cords, two sidewallsspaced apart a distance, which in the axial direction determines thegeneral width of the tire section, two beads each one of which aroundwhich are turned up the ends of the cords of the carcass, a treaddisposed on the crown of the carcass, and a belt structure that iscircumferentially disposed between the tread and the carcass, the beltstructure having a width that is substantially equal to that of thetread and having at least one layer of elastomeric fabric reinforcedwith metallic cords, said metallic cords in at least one layer being of7x12x0.25+1 construction with a gauge of 3.02 mm and a rivet of 1.44 mm.22. The pneumatic tire of claim 21 wherein the inch strength of said onelayer is 74,100 N.
 23. The pneumatic tire of claim 22 wherein the cordsare spaced at 5.7 EPI.
 24. The pneumatic tire defined in claim 12wherein belt structure includes first and second overlapped beltswherein said cords of said first and second belts are constructed of2+2x0.30.
 25. The pneumatic tire defined in claim 12 wherein beltstructure includes first and second overlapped belts wherein said cordsof said first and second belts are constructed of 2+2x0.35.
 26. Thepneumatic tire defined in claim 12 wherein belt structure includes firstand second overlapped belts wherein said cords of said first and secondbelts are constructed of 2x0.30.
 27. The pneumatic tire defined in claim12 wherein belt structure includes first and second overlapped beltswherein said cords of said first and second belts are constructed of2x0.35.
 28. The pneumatic tire defined in claim 12 wherein beltstructure includes first and second overlapped belts wherein said cordsof said first and second belts are constructed of 2+2x0.30.
 29. Thepneumatic tire defined in claim 12 wherein belt structure includes firstand second overlapped belts wherein said cords of said first and secondbelts are constructed of 2x0.23.
 30. The pneumatic tire defined in claim12 wherein belt structure includes first and second overlapped beltswherein said cords of said first and second belts are constructed of2x0.30.
 31. The pneumatic tire defined in claim 12 wherein beltstructure includes first, second, third and fourth radially overlappedbelts wherein said cords of each of said belts are constructed of3+2x0.33.
 32. The pneumatic tire defined in claim 31 further including aply having a cord of 1x0.24/6x0.22+1.
 33. The pneumatic tire defined inclaim 12 wherein belt structure includes first, second, third and fourthradially overlapped belts wherein said cords of each of said belts areconstructed of 3+4x0.38.
 34. The pneumatic tire defend in claim 33further including a ply having a cord of 1x0.24/6x0.22+1.
 35. Thepneumatic tire defined in claim 12 wherein belt structure includesfirst, second, third and fourth radially overlapped belts wherein saidcords of each of said first and fourth belts are constructed of 3+2x0.33UT and said cords of each said second and third belts, sandwichedbetween said first and fourth belts are constructed of 3+3x0.33.
 36. Thepneumatic tire defined in claim 35 further including a ply having a cordof 3x0.22/9x0.20+1.
 37. The pneumatic tire defined in claim 12 whereinbelt structure includes first, second, third and fourth radiallyoverlapped belts wherein said cords of each of said belts areconstructed of 3+4x0.38.
 38. The pneumatic tire defined in claim 37further including a ply having a cord of 3x0.22/9x0.20+1.